Reinforced laminated ski



p 194G. H. MCI... DAVEDSON 2,213,993

REINFORCED LAMINATED SKI I Filed Aug. 4, 1938 2 Sheets-Sheet l &\ \\&y{/i I 3 if J I Ma I N E N T O [Q Hamish M Leod Davidson.

ATTOFQNEY Sept. 3, 1940.

H. McL..- DAVIDSON REINFORCED LAMINATED SKI Filed Aug. 4, 1938 2Sheets-Sheet 2 I NV E N TD F Ham/Sh M Leod Davidson.

ATTOFQN EY Patented Sept. 3 1940 UNITED STATES REINFORCED LAMINATED SKIHamish McLeod Davidson, Vancouver, Province of British Columbia, CanadaApplicationAugust 4, 1938, Serial No 223,093

2 Claims.

This invention relates particularly to improved reinforced laminatedskis and aeroplane skis.

An object of the present invention is the provision of light,reinforcedlaminated skis or other laminated articles in which lightnessand durability are required.

Another object is the provision of means for reinforcing flexiblelaminated articles without affecting their pliability or materiallyincreasing their weight, or size.

Another object is the provision of means for increasing the flexibilityof laminated skis without decreasing the strength thereof.

Yet another object is the provision of means in laminated skis foraffording a better grip for screws, nails and other fasteners'that maybe used therewith.

Still another object is the provision of means in laminated skis forreducing splitting and breaking.

As is well known, skis require considerable flexibility at both theforward and tail ends thereof. The forward end must be flexible in orderthat the ski will bend and ride over any reasonably size-d obstaclesthat may be encountered while the tail end thereof must also be flexibleto prevent the ski from being broken by the weight of the skier afterthe middle point of the ski has passed over the obstacle. Unfortunately,flexibility is gained by making the ski relatively thin at the desiredpoints and these points of great flexibility are subjected to very greatand usually sudden strain. The forward end of the ski is constantlysubjected to sudden bending at high speeds which often results inbreakage at this point while the tail end is whipped about which resultsin the splitting of the wood from the end of the ski towards the middlethereof. Actually the whole ski is constantly placed under great strainand, therefore, must be made as strong as possible consistent with thenecessary flexibility and lightness thereof.

The lamination of skis in itself was an attempt to strengthen them aswell as to reduce their weight. This has been only partially successfulso that the breaking and splitting has been reduced very little. Anattempt has been made to reinforce the forward or upturned ends of skisby securing thereto metallic strips by means of nails, screws, rivets orthe like. This, however, has proven very detrimental to the skis formany reasons. The metal increases the weight of the skis at the forwardends thereof and throws them out of balance. The screws, nails or rivetsweaken the wood at the point of the greatest strain. The

,metal, being substantially non stretchable, pulls against the securingmeans under continual bending and, therefore, not only strains the woodbut loosens the securing means. filter in between the metal and the woodcausing the latter to expand and warp and eventually to rot and themetal is liable to rust. The metal cannot be bonded to the woodsuccessfully owing to the constant flexing thereof and to the well knowndifficulty of making According to the present invention, suitable meansis provided for reinforcing skis either throughout their entire lengthsor at any desired point or points. This reinforcing means is in itselflight, flexible and may be bonded to the wood.

The following drawings illustrate by way of example, a number of skismade up in accordance with the present invention, but it is to beunderstood that aeroplane' skis, runners, or the like come equally wellwithin the scope of this invention:

Figure 1 is a side elevation of the preferred form of ski,

Figure 2 is an enlarged section taken onthe line 2-2 of Fig. 1,

Figure 3 is a view of the sub-units of the ski shown in Fig. 1, beforethe final assembly thereof, and

Figures 4 and 7, inclusive, illustrate alternative ski constructions.

According to the present invention, the skis are provided with one ormore laminations or plies of thermo-set material, such as, for example,vulcanized fibre, laminated Bakelite, and plastic compositions. Theselaminations or plies of thermoset material may extend the full length ofthe skis or they may extend over any desired point or points, or the skimay include a combination of these. In this way, the skis are reinforcedthroughout their entire length or at any desired point or points by amaterial that in itself is durable, pliable and light and which may bereadily bonded to the ski.

Referring more particularly to Figs. l to 3, inclusive, of the drawings,the ski A comprises upper and lower laminations II and i2 and a centrallamination, ply or core l3, all formed of suitable wood. The core [3 isshorter than the plies H and I2 and it is comparatively thick atsubstantially'it's mid section and tapers towards each end thereof. Aply of thermo-set material I4 is interposed between the upper ply l land the core l3 and another ply of thermo-set material i5 is interposedbetween the lower ply l2 and the Moisture tends to I metal adhere towood. 10

core, said plies l4 and i5 extending substantially the full length ofthe ski. While the core I3 is illustrated as being. formed from a singlepiece of wood, it is to be understood that it may comprise a pluralityof laminations or plies of wood with or without plies of thermo-setmaterial interposed therebetween. If desired, the ski may be providedalong its lower edges with metal edges l6 secured thereto by securingmeans ll, such as small screws or nails, which extend into or throughthe lower material ply i5.

In this manner, the ski is formed with two plies or laminations ofthermo-set material that reinforce the ski throughout; its entire lengthwithout affecting its flexibility and without adding materially to itsweight. It will be noted that there are two plies of the thermo-setmaterial bonded together at the forward and tail ends of the ski whereit .is thinnest and where it is subjected to the greatest strain.

The various plies or laminations of the ski A may be bonded together inany suitable manner.

In Fig. 4, the ski consists of a lamination or ply of wood 20 which isrelatively thick at its mid section and tapers towards the ends thereof.The lamination 20 may be longitudinally slotted at either or both endsto receive one or more laminations or plies of thermo-set material 2|,These plies extend throughout the very thin portion of the ski where itmust be flexible and where it is subjected to the greatest strain.

Fig. 5 illustrates a ski made up of an upper ply or lamination 23 formedof wood, which is relatively thick at its mid section and tapers towardsthe ends thereof, a central lamination or ply of wood 26 and a lowerlamination or ply of thermo-set material 25. If desired, the upper ply23 may be formed of a plurality of laminations with or withoutinterposed layers of thermo-set material.

Fig. 6 shows a ski having a central ply or lamination 21 formed of woodwhich is relatively thick at its mid section and tapers towards the endsthereof. This ski also has a ply or lamina- .tion of thermo-set material28 bonded to the bottom of the ply 21 and/or a ply or lamination ofthermo-set material 29 bonded to the top of the central ply. If desired,the ply 28 may be formed of a plurality of laminations of wood with orwithout interposed layers of thermo-set material bonded togetheraccording to the present invention.

In Fig. 7, the ski is formed with an upper ply or lamination of wood 3|which is relatively thick at its mid section and tapers towards the endsthereof. A central ply or lamination of thermoset material 32 isinterposed between the ply 3| and a lower ply or lamination of wood 33.The upper ply 3! may be slotted to receive a single ply or lamination ofthermo-set material 36 below the upper surface thereof at itsmid-section or it may be formed of a plurality of pliesor laminations ofwood with or without interposed layers of thermo-set material which havebeen bonded in any suitable manner. a

Fig. 7 illustrates another alternative in which a ply or lamination ofthermo--set material 35 is bonded to the bottom of the ski at anydesired point but preferably at the forward endthereof. Obviously, theply 35 may be applied to any of the above described skis which do nothave a ply of thermo-set material along the bottom thereof.

The plies or laminations of thermo-set'material thus incorporated in theskis reinforce them at the desired points without affecting theflexibility thereof or without adding materially to their weight orthickness. In fact, the flexibility of the skis may be increased at thedesired points since the wooden plies may be made thinner owing to thegreatstrengthening effect of the thermo-set material plies. In most ofthese skis, the plies or laminations of thermoset material aiford abetter grip for screws, nails and other fastening means for ski harness,fittings, metal edges or the like.

From the above, it will readily be seen that means have been providedfor reinforcing skis to reduce splitting and breaking without affecting,and. in some cases, even increasing, the flexibility thereof or withoutadding materially to the weight or size thereof.

While only one type of ski has been described and illustrated, it is tobe understood that aeroplane skis may be reinforced-in a similar-manner.It is intended that the words thermo-set material as used in theforegoing specification and 1n the following claims, shall includematerials,

such as vulcanized fibre, laminated Bakelite, and plastic compositions,which are set by means of heat when they are manufactured.

Various modifications may be made in this invention without departingfrom the spirit thereof or the scope of the claims, and therefore theex-' act forms shown are'to be taken as illustrative only and not in alimiting sense, and it is desired that only such limitations shall beplaced thereon as are disclosed in the prior art or are set forth intheaccompanying claims.

What I claim as my invention is:

1. A laminated ski comprising a wooden core,

upper and lower wooden laminations having a length greater than thelength of said core, said core gradually tapering in the direction ofits ends, and upper and lower reinforcing composition laminationsinterposed between said core and said upper and lower wooden laminationsand adhesively secured thereto, said composition laminations adhesivelysecured to said core and said wooden laminations and adhesively securedtogether beyond the ends of said core to thereby form a reinforcingmeans at the point of greatest stress.

2. A laminated ski comprising a wooden core, upper and lower woodenlaminations having a length greater than the length of said core, saidcore gradually tapering in the direction of its ends, and upperreinforcing composition laminations interposed between said core andsaid up-

